1. Field of the Invention
The present invention relates to a method for producing β-hydroxy-α-L-amino acid and in particular, to a method for producing an L-serine derivative with a novel enzyme.
2. Brief Description of the Related Art
Derivatives of the amino acid serine and amino acids having optical activity in the a position are typically used as intermediates in the production of pharmaceuticals. Examples of methods for producing optically active α-alkyl serine derivatives, which have two different substituents in the α position, and salts thereof, include the following methods:
1) asymmetric alkylation of an optically active oxazolidine compound obtained from the optically active serine derivative and pivalaldehyde (Helvetica Chimica Acta, 1987, 70, 1194-1216);
2) asymmetric aldol reaction of α-isocyano carboxylic acid ester and paraformaldehyde with an optically active metal catalyst (Tetrahedron Letters, 1988, 29, 235-238);
3) asymmetric alkylation of optically active β-lactam compounds obtained from an optically active oxazolidine chromium carbene complex and an oxazine compound (Journal of Organic Chemistry, 1993, 58, 5918-5924);
4) asymmetric ring-opening reaction of an optically active aziridine compound (Tetrahedron Letters, 1995, 36, 3639-3642)
5) asymmetric alkylation of an optically active pyrazinone compound obtained from an optically active valine derivative and an optically active alanine derivative (European Journal of Organic Chemistry, 2000, 2809-2820); and
6) Sharpless asymmetric dihydroxylation of a 2-methyl-2-propenoic acid derivative followed by introduction of the resulting optically active diol compound into an optically active azido compound for reduction (Tetrahedron Asymmetry, 2001, 12, 949-957).
α-Methyl-L-serine is a promising substance which may be used as an intermediate in the production of a medicament. In one of the known methods for producing α-methyl-L-serine by means of an enzymatic reaction, D-alanine and 5,10-methylenetetrahydrofolic acid are used as the materials, and 2-methyl serine hydroxymethyl transferase (EC 2.1.2.7) is used as the enzyme (Wilson et al., J. Biol. Chem. 237 3171-3179).